Hi,
I’ve been generously offered a mattress of my choosing as a gift. I just was asked to purchase one sooner rather than later. (Within the next 2 weeks)
I’m a big guy. 36.5 BMI. 6’1. And a side sleeper. With lower back pain.
Looking for a firm full size mattress. Around a $1,000. (Slightly more is ok if it’s worth it.)
Any suggestions would be greatly appreciated.
Thank you.
Hi Polorsport,
Welcome to the Mattress Forum! 
That’s a wonderful (and useful) gift. Congratulations!
A high BMI presents special challenges and generally requires firmer materials (in the support layers especially). This could be firmer latex or innersprings (the type of support component would be a personal preference and in the right design either could be suitable) or even a zoned construction. The same overall guidelines apply with higher weights though that PPP (Posture and alignment, Pressure relief, and Personal preferences) along with using high quality durable materials that will maintain their feel and performance for longer periods of time are the way to make the best choices. Heavier people in general will need firmer and thicker comfort layers and firmer support layers than those who are lighter and because no materials will last as long with much higher weights the quality and durability of the materials and components is even more important than normal. I wouldn’t “rule out” any types of mattress and base your choices on your own personal testing. Post #3 here has more information and suggestions about higher BMIs that is worth reading.
The key will be finding componentry that will be of appropriate quality for your specific situation, which will then give you the best chance at have a successful comfort life, so I would always make sure that you find out the information listed here so you can compare the quality of the materials and components. Those in a higher BMI range want to be especially prudent in the choice of their components. For those in a higher BMI range, there is more information about selecting a mattress in the durability guidelines here. Specifically, if your BMI is 30 or higher:
Higher BMI ranges will need more durable materials and components in a mattress and in a BMI range of 30 or higher I would include any 1.8 lb polyfoam or 4 lb memory foam as a “lower quality/density” material (relative to a higher BMI only) and minimize their use to a total of “about an inch or so or less” in the mattress.
Polyurethane foam: If your mattress is one sided then I would look for 2.0 lb per cubic foot density or higher. If the mattress is two sided then I would use a minimum density of 1.8 lbs per cubic foot or higher.
Memory foam (or gel memory foam): If your mattress is one sided then I would make sure that any memory foam is at least 5 lb per cubic foot. If the mattress is two sided then I would use a minimum density of 4 lbs per cubic foot.
I’m sorry to learn of your low back issues. There is unfortunately no one firmness level that is “best for bad backs” in general because it would depend on the body type, sleeping style, and individual preferences of the person. A mattress needs to have deeper layers that are “firm enough” to stop the heavier parts of your body from sinking down too far and make sure you sleep with your spine and joints in good alignment and upper layers that are thick and soft enough to “allow” any pressure points such as the hips and shoulders to sink down far enough to relieve pressure points in all your sleeping positions as well but “firm enough” and “soft enough” can vary widely from person to person.
While I can certainly help with “how” to choose, it’s not possible to make specific suggestions or recommendations for either a mattress, manufacturers/retailers, or combinations of materials or components because the first “rule” of mattress shopping is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort”, firmness, or PPP (Posture and alignment, Pressure relief, and your own Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more reliable than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
The first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on all the parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
Outside of PPP (which is the most important part of “value”), the next most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t see or “feel” and assessing the durability and useful life of a mattress depends on knowing the specifics of its construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label or how a mattress feels in a showroom or when it is relatively new so I would always make sure that you find out the information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase (these are the same two articles I linked to earlier in my comments about a higher BMI).
In its simplest form … choosing the “best possible” mattress for any particular person really comes down to FIRST finding a few knowledgeable and transparent retailers and/or manufacturers (either locally or online) that sell the types of mattresses that you are most interested in that are in a budget range you are comfortable with and that you have confirmed will provide you with the all the information you need about the materials and components inside the mattresses they sell so you will be able to make informed choices and meaningful comparisons between mattresses and then …
Careful testing (hopefully using the testing guidelines in the tutorial) to make sure that a mattress is a good match for you in terms of “comfort”, firmness, and PPP … and/or that you are comfortable with the options you have available to return, exchange, or “fine tune” the mattress and any costs involved if you can’t test a mattress in person or aren’t confident that your mattress is a suitable choice.
Checking to make sure that there are no lower quality materials or weak links in a mattress you are considering relative to your higher BMI range that could compromise the durability and useful life of the mattress.
Comparing your finalists for “value” based on #1 and #2 and all the other parts of your personal value equation that are most important to you.
Hopefully this gives you a good start. If you have other questions after going through this material or visiting and testing out products, post them back here and I’ll do my best to be assistive.
Phoenix